REMOTE SENSING OF RIVER BANKFULL WIDTH IN NORTHERN NEW ENGLAND

Remote sensing techniques are revolutionizing earth system science, including the understanding of fluvial flooding and migration. Accurate topographic data for river corridors is required for hydraulic flood modeling, and repeated data for the same reach can characterize the location and magnitude of change in river planform location over time. We used river corridor topography obtained from structure-from-motion (SfM) photogrammetry, light detection and ranging (LiDAR) from un-personed aerial vehicles (UAVs), airplane-based LiDAR, as well as bankfull position delineations from aerial imagery, to characterize river width and channel change for river corridors in New Hampshire and Vermont. Bankfull widths estimated from remote sensing agreed well with field measurements, and remotely sensed bankfull widths were particularly accurate in regions where banks were clearly demarcated and unvegetated. Error in estimated bankfull widths depended on riverbank land cover and sediment type. Repeated flights were successfully used to characterize changes in river planform over time resulting from large flood events at a fraction of the effort required for field surveying. Remote sensing thus represents a promising method of better understanding fluvial form and function in the northeastern United States.